Ernst and Dina Marais were described as a “lovely couple” by a neighbor

The battered bodies of a retired married couple were found in a river in a world-famous national park.

Ernst and Dina Marais were found dead in Kruger National Park in South Africa on Friday, May 22, according to the Cape Times and The Sun.

The couple was last seen two days earlier on Wednesday, May 20, when they left their holiday accommodations for what was supposed to be a day of sightseeing.

he Kruger national park

Kruger National Park in South Africa.getty

Ernst, 71, and Dina, 73, were from Mossel Bay on the country’s southern coast, per the Cape Times.

It is believed that the couple was stabbed and that their hands were bound behind their backs, per The Sun.

“It was hoped that they had gone off road and [that their vehicle had] broken down after heavy local floods somewhere, but then we got a call to say two bodies had been found,” a Kruger National Park source said, per the outlet.

“Both had been stabbed in what was clearly a very brutal attack and had been thrown into the river, no doubt for the crocs, and their 4 x 4 had been stolen, so this is a very major incident for us,” the source added.

According to The Sun, an anonymous source within the South African police said investigators suspect that the couple may have encountered a group of poachers and were killed to prevent them from speaking out.

The source added, “Their pickup truck would have been an easy way to transport anything they were carrying if they were smugglers, and there are unfenced ways to get across the river into Mozambique.”

One of the couple’s neighbors told the outlet that police had been to their residence in Mossel Bay in the hopes that Ernst and Dina had simply returned home, but the house was empty.

he Kruger national park

Kruger National Park in South Africa.getty

“They were a lovely couple who loved going on safari, and the residents are all in shock,” the neighbor said, per The Sun.

South African National Parks (SANParks) confirmed “with shock and sadness” that two bodies were discovered in the Pafuri section of the park in a media release published on Saturday, May 23.

SANParks added that a full search operation had been launched “after camp staff noticed the tourists had not returned to camp.”

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The park service said the bodies were ultimately found “near a river” by other tourists in what was described as a “gruesome discovery.”

SANParks additionally confirmed that the couple’s vehicle is missing.

“It is the first time in the history of the Kruger National Park that an incident of this nature has been reported,” Minister of Forestry, Fisheries and the Environment Willie Aucamp said, per the release, adding that the victims’ next of kin have been informed.

Aucamp added that police are currently investigating the incident.

The South African Police Service did not immediately return PEOPLE’s request for comment.